package com.aurora.leetcode.answer;

public class searchInsert_35 {
    /**
     * 给定一个排序数组和一个目标值，在数组中找到目标值，并返回其索引。如果目标值不存在于数组中，返回它将会被按顺序插入的位置。
     * 请必须使用时间复杂度为 O(log n) 的算法。
     * */

    //answer one:
    public int searchInsert(int[] nums, int target) {
        int left = 0;
        int right = nums.length - 1;
        while(left < right){
            int mid = (left+right)/2;
            if(left == mid) break;
            if(target>nums[mid]){
                left = mid;
            }else if (target < nums[mid]){
                right = mid;
            }else{
                return mid;
            }
        }
        if(target > nums[right]) return right+1;
        if(target < nums[left]) return left - 1 <0?0:left-1;
        if(target == nums[left]) return left;
        if(target == nums[right]) return right;
        return left+1;
    }


    //official answer:
    public int searchInsert2(int[] nums, int target) {
        int left = 0;
        int right = nums.length - 1;
        while(left <= right){
            int mid = (right-left)>>2+left;
            if(target>=nums[mid]){
                left = mid+1;
            }else if (target < nums[mid]){
                right = mid-1;
            }
        }

        return left;
    }
}
